305902domain: NAppears in sequencesa(n) = Sum_{k=0..m} (k+1) * A026022(n, m-k), where m=n for n=0,1 and m = floor((n+3)/2) for n >= 2.at n=17A027299Number of nondecreasing -n..n vectors of length 4 whose dot product with some nonincreasing -n..n vector equals 4.at n=24A226401